Datacenters often include multiple power distribution units (PDU's) contained within equipment racks. Intelligent rack-mounted power distribution units, sometimes referred to as “rack PDU's,” provide power for multiple computing devices such as servers contained with the equipment racks. The computing devices typically use large amounts of energy. It is useful to measure the current and voltage used by each of the computing devices and other associated equipment such as cooling units to determine the overall efficiency of the datacenter. Current at an electrical outlet can be measured using wall plug-mounted devices or electrical power strips, but these units can become impractical in PDU's having multiple outlets.